U.S. patent application number 13/624822 was filed with the patent office on 2014-03-27 for method of removing damaged epoxy from electrostatic chuck.
This patent application is currently assigned to LAM RESEARCH CORPORATION. The applicant listed for this patent is LAM RESEARCH CORPORATION. Invention is credited to Rish Chhatre, Yan Fang, Tuochuan Huang, Cliff LaCroix, Neal Newton, Hong Shih.
Application Number | 20140083461 13/624822 |
Document ID | / |
Family ID | 50318568 |
Filed Date | 2014-03-27 |
United States Patent
Application |
20140083461 |
Kind Code |
A1 |
Shih; Hong ; et al. |
March 27, 2014 |
METHOD OF REMOVING DAMAGED EPOXY FROM ELECTROSTATIC CHUCK
Abstract
A method of removing an epoxy band from an electrostatic chuck
includes securing the electrostatic chuck in a servicing fixture,
applying a thermal source to the epoxy band to breakdown a
plurality of adhesive bonds securing the epoxy band to the
electrostatic chuck, forming a hole in the epoxy band and pulling
the epoxy band from the electrostatic chuck. A system for removing
an epoxy band from an electrostatic chuck is also described.
Inventors: |
Shih; Hong; (Walnut, CA)
; Huang; Tuochuan; (Saratoga, CA) ; Fang; Yan;
(Fremont, CA) ; LaCroix; Cliff; (Livermore,
CA) ; Newton; Neal; (San Jose, CA) ; Chhatre;
Rish; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LAM RESEARCH CORPORATION |
Fremont |
CA |
US |
|
|
Assignee: |
LAM RESEARCH CORPORATION
Fremont
CA
|
Family ID: |
50318568 |
Appl. No.: |
13/624822 |
Filed: |
September 21, 2012 |
Current U.S.
Class: |
134/19 ;
134/105 |
Current CPC
Class: |
B08B 1/00 20130101; B08B
7/0071 20130101; B08B 7/00 20130101; B08B 5/02 20130101; B08B 5/00
20130101; H01L 21/6833 20130101 |
Class at
Publication: |
134/19 ;
134/105 |
International
Class: |
B08B 7/00 20060101
B08B007/00 |
Claims
1. Method of removing an epoxy band from an electrostatic chuck
comprising: securing the electrostatic chuck in a servicing
fixture; applying a thermal source to the epoxy band to breakdown a
plurality of adhesive bonds securing the epoxy band to the
electrostatic chuck; forming a hole in the epoxy band; and pulling
the epoxy band from the electrostatic chuck.
2. The method of claim 1, wherein applying the thermal source to
the epoxy band to breakdown the plurality of adhesive bonds
securing the epoxy band to the electrostatic chuck includes:
determining a width of an outside surface of the epoxy band;
selecting a heated tip tool having a width less than the width of
the epoxy band; heating the selected heated tip tool to operating
temperature; and applying the heated tip tool to the outside
surface of the epoxy band to heat the epoxy band and breakdown a
plurality of adhesive bonds securing the epoxy band to the
electrostatic chuck.
3. The method of claim 2, wherein forming the hole in the epoxy
band includes: pressing the heated tip tool into the epoxy band to
forming the hole in the epoxy band.
4. The method of claim 2, wherein applying the heated tip tool to
the outside surface of the epoxy band includes applying heated air
having a temperature of between about 90 and 110 degrees C.
5. The method of claim 1, wherein applying the thermal source to
the epoxy band to breakdown the plurality of adhesive bonds
securing the epoxy band to the electrostatic chuck includes
applying a coolant to the epoxy band.
6. The method of claim 5, wherein applying a coolant to the epoxy
band includes: directing a coolant nozzle toward an outside surface
of the epoxy band, the coolant nozzle being coupled to a coolant
source.
7. The method of claim 5, wherein applying a coolant to the epoxy
band includes cooling the epoxy band to a temperature of between
about 40 degrees C. to about 100 degrees C. less than the
temperature of the electrostatic chuck.
8. The method of claim 5, wherein forming the hole in the epoxy
band and pulling the epoxy band from the electrostatic chuck
includes applying the coolant to the epoxy band at a pressure of
between about 50 psi to about 80 psi.
9. The method of claim 1, wherein the servicing fixture includes: a
perimeter frame having an inner diameter greater than an outer
perimeter of the electrostatic chuck; a plurality of extensions
extending from the inner diameter of the perimeter frame to near
the outer perimeter the electrostatic chuck; and a corresponding
plurality of fasteners, each one of the plurality of fasteners
extending through a corresponding one of the extensions toward the
outer perimeter the electrostatic chuck.
10. The method of claim 1, wherein pulling the epoxy band from the
electrostatic chuck includes pulling the epoxy band with a pick
tool.
11. The method of claim 10, wherein the pick tool is formed from a
material that is softer than a top layer and a surface of a base of
the electrostatic chuck.
12. System for removing an epoxy band from an electrostatic chuck
comprising: a servicing fixture including: a perimeter frame having
an inner diameter greater than an outer perimeter of the
electrostatic chuck; a plurality of extensions extending from the
inner diameter of the perimeter frame to near the outer perimeter
the electrostatic chuck; and a corresponding plurality of
fasteners, each one of the plurality of fasteners extending through
a corresponding one of the extensions toward the outer perimeter
the electrostatic chuck, securing the electrostatic chuck in the
servicing fixture; and a thermal source.
13. The system of claim 12, further comprising a pick tool formed
from a material that is softer than a top layer and a surface of a
base of the electrostatic chuck.
14. The system of claim 12, wherein the thermal source includes a
heated tip tool.
15. The system of claim 14, wherein the heated tip tool includes a
tip having a width less than a width of an outer surface of an
epoxy band on the electrostatic chuck.
16. The system of claim 12, wherein the thermal source includes a
coolant nozzle coupled to a coolant source and directed toward an
outer surface of an epoxy band on the electrostatic chuck.
17. The system of claim 12, servicing fixture includes a plurality
of legs for supporting the servicing fixture away from a work
surface.
18. Method of removing an epoxy band from an electrostatic chuck
comprising: securing the electrostatic chuck in a servicing
fixture; applying a previously heated heated tip tool to the
outside surface of the epoxy band to heat the epoxy band and
breakdown a plurality of adhesive bonds securing the epoxy band to
the electrostatic chuck; forming a hole in the epoxy band;
directing a coolant nozzle toward the hole in the epoxy band, the
coolant nozzle being coupled to a coolant source applying the
coolant to the hole in the epoxy band at a pressure of between
about 50 psi to about 80 psi; and blowing the epoxy band from the
electrostatic chuck with the pressurized coolant flow.
19. The method of claim 18, wherein applying the coolant to the
hole in the epoxy band cools the epoxy band to a temperature of
between about 40 degrees C. to about 100 degrees C. less than the
temperature of the electrostatic chuck.
Description
BACKGROUND
[0001] The present invention relates generally to semiconductor
process chambers and more particularly, to systems, methods and
apparatus for refurbishing an electrostatic chuck from a
semiconductor process chamber.
[0002] Semiconductor process chambers typically use an
electrostatic chuck to secure the workpiece (e.g., semiconductor
wafer) as the workpiece is being processed (e.g., etched, cleaned,
imaged, deposition processes, etc.).
[0003] Unfortunately, the various processing of the workpiece can
also cause unwanted deposits (e.g., etch residue polymers,
particles, etc.) to form and adhere to the electrostatic chuck. The
unwanted deposits can also flake off or otherwise transfer from the
electrostatic chuck to contaminate the present or a subsequent
workpiece being secured to the electrostatic chuck for
processing.
[0004] The electrostatic chuck is periodically removed from the
processing chamber and replaced with a new electrostatic chuck to
prevent the contamination of workpieces. The electrostatic chuck is
a complex and expensive component of the semiconductor process
chamber. Replacing the electrostatic chuck increases the cost of
operation of the semiconductor process chamber.
[0005] In view of the foregoing, there is a need for an effective
electrostatic chuck refurbishing system, method and apparatus so a
refurbished electrostatic chuck can be reused.
SUMMARY
[0006] Broadly speaking, the present invention fills these needs by
providing an electrostatic chuck refurbishing system, method and
apparatus. It should be appreciated that the present invention can
be implemented in numerous ways, including as a process, an
apparatus, a system, computer readable media, or a device. Several
inventive embodiments of the present invention are described
below.
[0007] One embodiment provides a method of removing an epoxy band
from an electrostatic chuck including securing the electrostatic
chuck in a servicing fixture, applying a thermal source to the
epoxy band to breakdown adhesive bonds securing the epoxy band to
the electrostatic chuck, forming a hole in the epoxy band and
pulling the epoxy band from the electrostatic chuck.
[0008] Applying the thermal source to the epoxy band to breakdown
the adhesive bonds securing the epoxy band to the electrostatic
chuck can include determining a width of an outside surface of the
epoxy band, selecting a heated tip tool having a width less than
the width of the epoxy band, heating the selected heated tip tool
to operating temperature and applying the heated tip tool to the
outside surface of the epoxy band to heat the epoxy band and
breakdown a plurality of adhesive bonds securing the epoxy band to
the electrostatic chuck.
[0009] Forming the hole in the epoxy band can include pressing the
heated tip tool into the epoxy band to forming the hole in the
epoxy band. Applying the heated tip tool to the outside surface of
the epoxy band can include applying heated air having a temperature
of between about 90 and 110 degrees C.
[0010] Applying the thermal source to the epoxy band to breakdown
the adhesive bonds securing the epoxy band to the electrostatic
chuck can include applying a coolant to the epoxy band. Applying a
coolant to the epoxy band can include directing a coolant nozzle
toward an outside surface of the epoxy band, the coolant nozzle
being coupled to a coolant source. Applying a coolant to the epoxy
band can include cooling the epoxy band to a temperature of between
about 40 degrees C. to about 100 degrees C. less than the
temperature of the electrostatic chuck. Forming the hole in the
epoxy band and pulling the epoxy band from the electrostatic chuck
can include applying the coolant to the epoxy band at a pressure of
between about 50 psi to about 80 psi.
[0011] The servicing fixture can include a perimeter frame having
an inner diameter greater than an outer perimeter of the
electrostatic chuck, multiple extensions extending from the inner
diameter of the perimeter frame to near the outer perimeter the
electrostatic chuck and a corresponding multiple fasteners, each
one of the fasteners extending through a corresponding one of the
extensions toward the outer perimeter the electrostatic chuck.
[0012] Pulling the epoxy band from the electrostatic chuck can
include pulling the epoxy band with a pick tool. The pick tool can
be formed from a material that is softer than a top layer and a
surface of a base of the electrostatic chuck.
[0013] Another embodiment provides a system for removing an epoxy
band from an electrostatic chuck. The system includes a servicing
fixture and a thermal source. The servicing fixture includes a
perimeter frame having an inner diameter greater than an outer
perimeter of the electrostatic chuck, multiple extensions extending
from the inner diameter of the perimeter frame to near the outer
perimeter the electrostatic chuck and a corresponding set of
fasteners, each one of the fasteners extending through a
corresponding one of the extensions toward the outer perimeter the
electrostatic chuck, securing the electrostatic chuck in the
servicing fixture.
[0014] The system can also include a pick tool formed from a
material that is softer than a top layer and a surface of a base of
the electrostatic chuck. The thermal source can include a heated
tip tool. The heated tip tool having a tip width less than a width
of an outer surface of an epoxy band on the electrostatic
chuck.
[0015] The thermal source can include a coolant nozzle coupled to a
coolant source and directed toward an outer surface of an epoxy
band on the electrostatic chuck. The servicing fixture can include
multiple legs for supporting the servicing fixture away from a work
surface.
[0016] Yet another embodiment provides a method of removing an
epoxy band from an electrostatic chuck. The method includes
securing the electrostatic chuck in a servicing fixture, applying a
previously heated heated tip tool to the outside surface of the
epoxy band to heat the epoxy band to breakdown multiple adhesive
bonds securing the epoxy band to the electrostatic chuck. A hole is
formed in the epoxy band. A coolant nozzle is directed toward the
hole in the epoxy band, the coolant nozzle being coupled to a
coolant source. The coolant is applied to the hole in the epoxy
band at a pressure of between about 50 psi to about 80 psi and
blowing the epoxy band from the electrostatic chuck with the
pressurized coolant flow.
[0017] Other aspects and advantages of the invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be readily understood by the
following detailed description in conjunction with the accompanying
drawings.
[0019] FIG. 1 is a simplified diagram of a plasma processing
chamber, in accordance with embodiments of the present
invention.
[0020] FIG. 2A is a simplified diagram of the electrostatic chuck,
in accordance with embodiments of the present invention.
[0021] FIG. 2B is a top view of the electrostatic chuck, in
accordance with embodiments of the present invention.
[0022] FIG. 2C is a bottom view of an electrostatic chuck, in
accordance with embodiments of the present invention.
[0023] FIG. 2D is a detailed view of a side portion of the
electrostatic chuck, in accordance with embodiments of the present
invention.
[0024] FIG. 2E is a detailed side section view 2E-2E of the
electrostatic chuck, in accordance with embodiments of the present
invention.
[0025] FIGS. 3A and 3B are simplified diagrams of the electrostatic
chuck mounted in a servicing fixture, in accordance with
embodiments of the present invention.
[0026] FIGS. 4A-4D are simplified diagrams of removing the epoxy
band with a heated tip tool, in accordance with embodiments of the
present invention.
[0027] FIG. 5 is a flowchart diagram that illustrates the method
operations performed in removing the epoxy band with a heated tip
tool, in accordance with embodiments of the present invention.
[0028] FIGS. 6A-6C are simplified diagrams of using a coolant
nozzle to remove the epoxy band, in accordance with embodiments of
the present invention.
[0029] FIG. 7 is a flowchart diagram that illustrates the method
operations performed in removing the epoxy band with a coolant
nozzle, in accordance with embodiments of the present
invention.
[0030] FIG. 8A is a detailed side section view 2E-2E of the
electrostatic chuck with new epoxy band installed, in accordance
with embodiments of the present invention.
[0031] FIG. 8B is a detailed side section view 2E-2E of the
electrostatic chuck with an o-ring installed instead of a new epoxy
band, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
[0032] Several exemplary embodiments for an electrostatic chuck
refurbishing system, method and apparatus will now be described. It
will be apparent to those skilled in the art that the present
invention may be practiced without some or all of the specific
details set forth herein.
[0033] The electrostatic chuck can become contaminated by the
various processes conducted on the workpiece secured to the
electrostatic chuck. As a result, the electrostatic chuck must be
periodically cleaned and refurbished.
[0034] FIG. 1 is a simplified diagram of a plasma processing
chamber 100, in accordance with embodiments of the present
invention. The plasma processing chamber 100 includes a top
electrode assembly 102, an electrostatic chuck 140, and a workpiece
130 secured to the electrostatic chuck 140. The plasma processing
chamber 100 is also coupled to one or more process gas sources 112
for delivering process gases to the plasma processing chamber.
[0035] A top bias voltage source 114 is coupled to the top
electrode 102. A bottom bias voltage source 116 is coupled to the
electrostatic chuck 140. A controller 110 is coupled to the plasma
processing chamber 100, the one or more process gas sources 112,
the top bias voltage source 114 and the bottom bias voltage source
116. The controller 110 includes logic, operating system,
operations software and recipes for operating the plasma processing
chamber 100 during the various plasma and non-plasma processes
conducted in the plasma processing chamber.
[0036] FIG. 2A is a simplified diagram of the electrostatic chuck
140, in accordance with embodiments of the present invention. FIG.
2B is a top view of the electrostatic chuck, in accordance with
embodiments of the present invention. FIG. 2C is a bottom view of
an electrostatic chuck, in accordance with embodiments of the
present invention. The electrostatic chuck 140 includes a top layer
210 that is manufactured from a ceramic material capable of
withstanding the thermal and chemical stresses of the processes
conducted in the processing chamber 100.
[0037] A top edge ring 122A (shown in FIG. 1) is adjacent to the
perimeter of the top layer 210. A bottom edge ring 122B supports
the top edge ring 122A and is adjacent to the outer perimeter 220A
of the base 220 (shown in FIG. 1).
[0038] The top surface 202 of the top layer 210 includes one or
more sets of coolant holes 202A, 202B for delivering a cooling gas
flow to a backside of the workpiece 130. The backside of the
workpiece 130 is the surface of the workpiece in contact with the
electrostatic chuck 140 and opposite the surface 130A exposed to
the plasma 150. The one or more sets of coolant holes 202A, 202B
are shown in concentric rings, however, it should be understood
that the one or more sets of coolant holes can be arranged in more
than two rings and in other configurations and varying densities as
the coolant holes are distributed radially from near a center of
the top surface 202 to outward toward an outer perimeter of the top
surface 202.
[0039] The top layer 210 can also include electrodes 222A, 222B,
224A, 224B and lift pin holes 203A-C. Lift pins (not shown) can be
moved in an upward and a downward direction, substantially
perpendicular with the top surface 202, within the lift pin holes
203A-C. The lift pins can extend above the top surface 202 to lift
the workpiece 130 away from the top surface. The lift pins 203A-C
can also be retracted into the top layer 210 to lower the workpiece
130 to the top surface 202. It should be noted that the lift pin
holes 203A-C are shown disproportionately large relative to a
diameter of the top layer 210 for ease of illustration and
discussion.
[0040] The top layer 210 is coupled to a base 220 by a bonding
layer 236. The base 220 is typically a metal material such as
aluminum or stainless steel. An epoxy band 230 seals an outer edge
of the bonding layer 236 between the top layer 210 and the base
220. The bonding layer 236 thermally couples the top layer 210 to
the base 220 while also allowing for any differing thermal
expansion and contraction rates of the ceramic top layer and the
metallic base.
[0041] FIG. 2D is a detailed view of a side portion 270 of the
electrostatic chuck 140, in accordance with embodiments of the
present invention. FIG. 2E is a detailed side section view 2E-2E of
the electrostatic chuck 140, in accordance with embodiments of the
present invention.
[0042] As shown in FIG. 2E, the base has a height of dimension D1
of between about 10.0 mm and about 40.0 mm. The top layer 210 has a
height of dimension D2 of between about 3.0 mm and about 20.0 mm.
The bonding layer 236 and the epoxy band 230 have a thickness of
dimension D3 of between about 1.0 mm and about 10.0 mm.
[0043] The outer edge 230A of the epoxy band 230 and the outer edge
210A of the top layer 210 are substantially aligned. The outer
perimeter 220A of the base 230 extends outward from the outer edge
210A of the top layer 210 a dimension D4 of between about 5.0 mm
and about 25.0 mm, thus forming a step portion 212 of the base 220.
The epoxy band 230 extends under the top layer 210 a dimension D5
of between about 1.0 mm and about 10.0 mm from the top layer outer
edge 210A.
[0044] The top edge ring 122A and a bottom edge ring 122B are shown
in phantom in FIG. 2E. The top edge ring 122A overlaps the step
portion 212 toward the outer edge 210A of the top layer 210. A top
surface 122C of the top edge ring 122A can be substantially co
planar with the top surface 130A of the workpiece 130.
Alternatively, the top surface 122C of the top edge ring 122A can
be substantially coplanar (not shown) with the top surface 202 of
the electrostatic chuck 140.
[0045] A gap 124, having a width D6 of between about 0.5 mm and
about 2.0 mm, separates the top edge ring 122A from the outer edge
210A of the top layer 210. The gap 124 allows for differing thermal
expansion and contraction of the top edge ring 122A and the top
layer 210.
[0046] The epoxy band 230 forms a first adhesive bond 234 to the
bonding layer 236. The epoxy band 230 also forms a second adhesive
bond 211 to a bottom surface 202B of the top layer 210. The epoxy
band 230 also forms a third adhesive bond 213 to a top surface 220A
of the base 220. The epoxy band 230 effectively seals and protects
the bonding layer 236 from the processing chamber through adhesive
bonds 211, 213, 234.
[0047] The gap 124 allows for a portion of the plasma etch and
cleaning byproducts to reach the outer edge 230A of the epoxy band
230. The plasma etch and cleaning byproducts can damage the epoxy
band 230. The damage can include polymer (e.g., etch and cleaning
byproducts) build-up on the outer edge 230A of the epoxy band 230.
The damage can also include degradation of the material in the
epoxy band 230. In either instance, the damage to the epoxy band
230 can generate particles that may become detached from the outer
edge 230A of the epoxy band 230 and migrate through the gap 124 to
the surface 202 of the top layer 210 and contaminate the present
workpiece 130 secured to the electrostatic chuck 140 and/or a
subsequent workpiece.
[0048] Periodic removal and replacement of the epoxy band 230 is
one approach to substantially eliminate the epoxy band as a source
of contamination in the electrostatic chuck 140. The epoxy band 230
can be replaced with a new epoxy band 230' or with a plastic band
830 (e.g., an elastomer o-ring of suitable material such as a
perfluroroelastomer material.
[0049] FIGS. 3A and 3B are simplified diagrams of the electrostatic
chuck 140 mounted in a servicing fixture 300, in accordance with
embodiments of the present invention. The servicing fixture 300
provides a secure handling of the electrostatic chuck 140 for
servicing. The servicing fixture 300 can be made from any suitable
material such as a plastic, PTFE (Polytetrafluoroethylene), nylon,
steel, aluminum or other metal or ceramic material or any other
suitable materials and combinations thereof.
[0050] The servicing fixture 300 includes a perimeter frame 302
that has an inner diameter D7 greater than a diameter of the D8 of
the base 220 of the electrostatic chuck 140. The servicing fixture
300 also includes extensions 304 that extend from the perimeter
frame 302 to near the outer perimeter 220A of the base 220. The
servicing fixture 300 is shown having a substantially circular
outer perimeter, however it should be understood that the outer
perimeter of the servicing fixture could be any suitable shape.
Other shapes including elliptical, rectangular and other desired
shapes of electrostatic chucks can be similarly handled and
refurbished as described herein. A correspondingly shaped (e.g.,
elliptical, rectangular and other desired shape) servicing fixture
can also be used. The servicing fixture 300 can also be coupled to
one or more additional assemblies including, for example, a work
table, an articulating arm, a rotary table or other suitable
tooling and fixtures that may aid in the servicing of the
electrostatic chuck 140.
[0051] The base 220 includes multiple tapped holes 232 that
correspond to the extensions 304. It should be noted that while
four extensions 304 and four corresponding holes 232 are
illustrated, it should be understood that the servicing fixture 300
can include three or more extensions 304 and the base 220 can
include a corresponding number of tapped holes 232. Each one of a
corresponding number of bolts 232A or other type of suitable
fasteners extend through the extensions 304 and thread into the
corresponding tapped hole 232 to secure the electrostatic chuck 140
for servicing. It should also be understood that the extensions 304
can be threaded and the bolts 232A can engage the threads in the
extensions 304 to create a clamping action around the perimeter of
the electrostatic chuck base 220 with or without use of the holes
232 or threads tapped in the holes 232.
[0052] The servicing fixture 300 also includes three or more top
legs 334A and three or more bottom legs 334B. The top legs 334A and
the bottom legs 334B support the electrostatic chuck 140 away from
a work surface 340 during servicing.
[0053] The epoxy band 230 can be removed from the electrostatic
chuck 140 through numerous methods and tools (e.g., grinding,
solvents, etc) however many methods are not sufficiently effective
for various reasons. Some exemplary reasons for not being
sufficiently effective include too slow, excessively labor and/or
time intensive, excessive generation of waste streams (e.g., used
solvents), excessive risk of damaging the electrostatic chuck 140
and cost. Two methods, or combinations thereof, are described for
the removing the epoxy band 230.
[0054] Thermal effects such as heating or cooling the epoxy band
230 to a different temperature than the remaining portions of the
electrostatic chuck are utilized to ease removal the epoxy band.
The epoxy band 230 is a strong glue forming secure bonds 211, 213
and 234. Thus, the epoxy band 230 is difficult to physically pick
away from the outer perimeter of the bonding layer 236. It is
important to recall that the top layer 210 is a very expensive,
relatively fragile ceramic material and even one small chip can
ruin the entire top layer 210. It is also important to note that
the top surface 220A of the base 220 can be damaged (e.g., gouged,
scratched, etc.) if not handled carefully. Thus, the removal tool
should avoid physical contact with the top layer 210 and the top
surface 220A of the base 220 to prevent additional damage during
the removal process.
[0055] FIGS. 4A-4D are simplified diagrams of removing the epoxy
band 230 with a heated tip tool 402, in accordance with embodiments
of the present invention. The heated tip tool 402 has a width D9
that is less than the thickness D3 of the epoxy band 230. By way of
example, the heated tip tool 402 has a width D9 that is about 1.0
mm less than the thickness D3 of the epoxy band 230. The width D9
of the heated tip tool 402 is less than the thickness D3 of the
epoxy band 230 so that the heated tip tool 402 can apply heat to
the outer surface 230A of the epoxy band 230 without contacting
either of the bottom surface 202B top layer 210 or the top surface
220B of the base 220. The heated tip tool 402 can heat the outer
surface 230A of the epoxy band 230 to between about 115 degrees C.
and about 200 degrees C. The heated tip tool 402 can be a soldering
iron type tool with an appropriately sized and shaped heated tip.
The heated tip tool 402 is heated to about 155 degrees C. or
higher.
[0056] FIG. 5 is a flowchart diagram that illustrates the method
operations 500 performed in removing the epoxy band 230 with a
heated tip tool 402, in accordance with embodiments of the present
invention. The operations illustrated herein are by way of example,
as it should be understood that some operations may have
sub-operations and in other instances, certain operations described
herein may not be included in the illustrated operations. With this
in mind, the method and operations 500 will now be described.
[0057] In an operation 502, the electrostatic chuck 140 is removed
from the processing chamber 100. The electrostatic chuck 140 is
then inspected for any damage on the top layer 210 and the
remainder of the electrostatic chuck in an operation 504.
[0058] In an operation 506 the electrostatic chuck 140 is secured
in the service fixture 300. The outer surface 230A of the epoxy
band 230 is inspected for a presence of any etching or cleaning
byproduct deposits on the epoxy band in an operation 508. Minor
etching or cleaning byproduct deposits on the epoxy band 230 can be
removed using cleanroom suitable wipes and isopropyl alcohol (IPA)
to carefully wipe the outer surface 230A in an operation 510.
[0059] In an operation 512 the dimension D3 is measured on the
electrostatic chuck 140. A heated tip tool 402 having a width of
about 1.0 mm less than the measured dimension D3 is selected in an
operation 514.
[0060] In an operation 520, the heated tip tool 402 is heated to
operating temperature of about 155 degrees C. or higher. In an
operation 522, the heated tip tool 402 is applied to the outer
surface 230A of the epoxy band 230. The heated tip tool 402 is
applied to the outer surface 230A for between about 10 seconds and
about 60 seconds or longer so as to sufficiently heat and soften
the epoxy band 230 proximate to the heated tip tool 402. The heated
tip tool 402 heats the epoxy band 230 to between about 115 degrees
C. and about 200 degrees C. A minimum angle .alpha. is maintained
between the heated tip tool 402 and the top surface 220A of the
base 220 to avoid contact with and damage to the top layer 210 and
the top surface 220A of the base 220. Angle .alpha. is shown
exaggerated for illustration purposes. Angle .alpha. is typically
very near zero degrees so that the centerline of the heated tip
tool 402 and the step portion 212 of the base 220 are substantially
parallel. Excessive angle .alpha. can cause damage to the top layer
210 or the base 220.
[0061] In an operation 524, an additional physical pressing force
applied on the outer surface 230A by the heated tip tool 402. The
additional physical pressing force will force the heated tip tool
402 into the epoxy band 230 and create a corresponding hole in the
epoxy band, as shown in FIG. 4B. Heating the epoxy band 230 breaks
down bonds 211, 213 and 234 and in an operation 526, the epoxy band
will begin to come out of the space between the top layer 210 and
the top surface 220A of the base 220, as shown in FIG. 4C. The
heated tip tool 402 should not fully pierce the epoxy band 230 and
through the bond 234 as that can damage the bonding layer 236. A
suitable heat gun can also be used to heat the epoxy band 230 to
between about 90 to about 110 degrees C. or warmer to weaken and
breakdown the bonds 211, 213 and 234 to assist in the removal of
the epoxy band.
[0062] In an operation 530, a special designed pick tool 420 can be
used to carefully pick the epoxy band 230 starting from the hole
formed by the heated tip tool 402, as shown in FIG. 4D. The pick
tool 420 can be formed of any suitable material, preferably a
material that is softer than the ceramic top layer 210 and the
surface of the base 220 so that the pick tool 420 will not
unintentionally damage or scratch the ceramic top layer or the
surface of the base. Maintaining an acute angle .alpha. between the
pick tool 420 and the top surface 220A of the base 220 avoids
contact with a potential damage to the top layer 210 and the top
surface 220A of the base 220. In an operation 532, the
electrostatic chuck 140 is rotated so that the pick can pull out
the epoxy band 230 around the complete perimeter of the
electrostatic chuck.
[0063] In an operation 540, the epoxy band 230 is fully removed
from the electrostatic chuck 140. In operations 542-544, IPA and
de-ionized (DI) water are used in repetitive iterations to clean
the gap between the top layer 210 and the base 220 until any
residual epoxy is removed in an operation 546. In an optional
operation 548, additional cleaning of the electrostatic chuck 140
can be performed, as needed, and the method operations can end.
[0064] Applying a coolant to the epoxy band 230 can weaken the
bonds 211, 213 and 234 and thus allowing the epoxy band to be
removed from the electrostatic chuck. Using a coolant to remove the
epoxy band 230 is especially useful in refurbishing electrostatic
chucks where the dimension D3 is less than about 3.0 mm. When D3 is
less than about 3.0 mm, it is difficult to insert a heated tip tool
402 into the epoxy band 230 without damaging either the ceramic top
surface 210 or the surface 220B of the base 220. FIGS. 6A-6C are
simplified diagrams 600 of using a coolant nozzle 602 to remove the
epoxy band 230, in accordance with embodiments of the present
invention. FIG. 7 is a flowchart diagram that illustrates the
method operations 700 performed in removing the epoxy band 230 with
a coolant nozzle 602, in accordance with embodiments of the present
invention. The operations illustrated herein are by way of example,
as it should be understood that some operations may have
sub-operations and in other instances, certain operations described
herein may not be included in the illustrated operations. With this
in mind, the method and operations 700 will now be described.
[0065] In an operation 702, the electrostatic chuck 140 is removed
from the processing chamber 100. The electrostatic chuck 140 is
then inspected for any damage on the top layer 210 and the
remainder of the electrostatic chuck in an operation 704.
[0066] In an operation 706 the electrostatic chuck 140 is secured
in the service fixture 300. The outer surface 230A of the epoxy
band 230 is inspected for a presence of any etching or cleaning
byproduct deposits on the epoxy band in an operation 708. Minor
etching or cleaning byproduct deposits on the epoxy band 230 can be
removed using cleanroom suitable wipes and isopropyl alcohol (IPA)
to carefully wipe the outer surface 230A in an operation 710.
[0067] In an operation 712, a coolant nozzle 602 is directed to the
outer surface 230A of the epoxy band. The coolant nozzle 602 is
coupled to a coolant supply 610. The coolant has a temperature of
between about 40 degrees C. to about 100 degrees C. less than the
temperature of the electrostatic chuck 140. Exemplary coolants
include carbon dioxide (CO2). CO2 has a temperature of between
about -40 and -80 degrees C. as emitted from the nozzle 602 at
pressure of between about 50 psi to about 80 psi. It should be
understood that CO2 is an exemplary coolant and other coolants
capable of cooling the epoxy band 230 temperature of between about
40 degrees C. to about 100 degrees C. less than the temperature of
the electrostatic chuck 140 can also be used. The suitable coolants
can be liquid, gaseous or solid form. By way of example, dry ice
(solid CO2) can be used to cool the epoxy band 230 sufficiently to
break the adhesive bonds.
[0068] The coolant rapidly cools the epoxy band 230 causing the
epoxy band to be come hard and easily fractured or broken in an
operation 714. The cooled epoxy band 230 contracts, as shown in
FIG. 6B and pulls away from or otherwise defeats adhesive bonds
211, 213, 234, in an operation 716.
[0069] In an operation 720, the contracted epoxy band 230 fractures
under the pressure and cooling effects of the coolant. A pick tool
420 can also be used to assist in fracturing the epoxy band 230. In
an operation 722, the fractured epoxy band 230 is blown out of the
gap between the top layer 210 and the base 220. In an operation
724, the electrostatic chuck 140 is rotated so that the coolant can
blow out the epoxy band 230 around the complete perimeter of the
electrostatic chuck.
[0070] In an operation 730, the epoxy band 230 is fully removed
from the electrostatic chuck 140. In operations 732-734, IPA and DI
water are used in repetitive iterations to clean the gap between
the top layer 210 and the base 220 until any residual epoxy is
fully removed in an operation 736. In an optional operation 738,
additional cleaning of the electrostatic chuck 140 can be
performed, as needed, and the method operations can end.
[0071] It should be understood that the two methods of heating the
epoxy band 230 as described in FIGS. 4A-5, and cooling the epoxy
band as described in FIGS. 6A-7, can be used individually or in
combination. By way of example, the epoxy band 230 can be heated
and then cooled by a coolant to increase the thermal impact to the
adhesive bonds 211, 213, 234.
[0072] The above described two methods easily remove the epoxy band
230 with less risk to damaging the electrostatic chuck 140. The
above described two methods also easily remove the epoxy band 230
without use of aggressive chemical solvents. The above described
two methods also economically, efficiently remove the epoxy band
230 thus preparing the electrostatic chuck 140 for the next steps
in refurbishment.
[0073] FIG. 8A is a detailed side section view 2E-2E 800 of the
electrostatic chuck 140 with new epoxy band installed, in
accordance with embodiments of the present invention. After the
epoxy band 230 is fully removed and any epoxy band residue is
removed, the electrostatic chuck can be refurbished and a new epoxy
band 230' installed as shown in FIG. 8A.
[0074] FIG. 8B is a detailed side section view 2E-2E 820 of the
electrostatic chuck 140 with an o-ring 830 installed instead of a
new epoxy band 203', in accordance with embodiments of the present
invention. After the epoxy band 230 is fully removed and any epoxy
band residue is removed, the electrostatic chuck can be refurbished
and an o-ring 830 installed as shown in FIG. 8B.
[0075] With the above embodiments in mind, it should be understood
that the invention may employ various computer-implemented
operations involving data stored in computer systems. These
operations are those requiring physical manipulation of physical
quantities. Usually, though not necessarily, these quantities take
the form of electrical or magnetic signals capable of being stored,
transferred, combined, compared, and otherwise manipulated.
Further, the manipulations performed are often referred to in
terms, such as producing, identifying, determining, or
comparing.
[0076] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it will be
apparent that certain changes and modifications may be practiced
within the scope of the appended claims. Accordingly, the present
embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details
given herein, but may be modified within the scope and equivalents
of the appended claims.
* * * * *